In order to prevent damage from the impact of foreign objects such as birds or reduce or prevent erosion, a metallic sheath has been used to protect the leading edges of fan blades, rotor blades, and propellers. Materials such as titanium, steel, nickel and their alloys have been fitted on the leading edge of the element to be protected.
Sheaths can be formed and attached to an airfoil in various ways. For example, sheaths can be machined from metal and then bonded to the leading edge of an airfoil with adhesive, heat and pressure. Other methods of manufacturing a sheath include electroforming and powder laser deposition.